Lower risk of mortality in association with increased vitamin D

April 2, 2014. A review and meta-analysis published on April 1, 2014 in the British Medical Journal adds more evidence to an association between a higher serum level of vitamin D and a lower risk of death from any cause over follow-up periods ranging from 0.3 to 29 years.? The international team of researchers also uncovered a reduction in the risk of premature death in association with the use of vitamin D3 supplements.

Rajiv Chowdhury and colleagues selected 73 observational cohort studies that reported serum 25-hydroxyvitamin D levels and the cause of deaths that occurred among 849,412 men and women over follow-up. The analysis uncovered a 35% higher risk of death from cardiovascular disease or from any cause over follow-up among those whose vitamin D levels were in the lowest one-third of subjects in comparison with those whose levels were among the highest third. For non-vascular, non-cancer deaths, the risk was 30% higher and for cancer deaths, the risk was 14% higher among those in the lowest one-third of serum vitamin D.

Analysis of 22 randomized controlled trials of vitamin D supplements, involving a total of 30,716 participants, revealed an 11% lower risk of dying over three to seven years of follow-up among those who received vitamin D3 in comparison with a placebo or no treatment. As possible mechanisms for vitamin D in the prevention of premature mortality, the authors list a range of biological responses activated by vitamin D, involvement of the vitamin in gene regulation, association with increased white blood cell telomere length, and a relationship between low levels of vitamin D with suboptimal lifestyle and socioeconomic circumstances.

They recommend further investigations to establish optimal vitamin D3 dose and duration.